InChI=1S/C15H20O6S/c1-2-3-9-14(17)10-7-5-4-6-8-11-15(12-13-16)21-22(18,19)20/h1,7,10,13-15,17H,4-6,8,11-12H2,(H,18,19,20)/b10-7+